Simple Network Management Protocol (SNMP) and Remote Network Monitoring (RMON) are standards that provide a set of protocols for network management and control, including a specification for a data structure, and a set of data objects. SNMP and RMON are implemented in a network using one or more collection mechanisms such as, a probe or an agent, and management information bases (MIBs), which contain MIB objects specifying the data to be collected and other information pertinent to the purpose of network monitoring.
RMON utilizes SNMP to provide standard information that a network administrator can use to monitor, analyze, and troubleshoot a group of distributed network devices to determine an operational characteristic of a network or one or more network devices. RMON capabilities are defined by the Internet Engineering Task Force (IETF) in Request For Comment (RFC) 1757. RFC 1757 defines a probe capable of monitoring an Ethernet segment and transmitting statistical information back to an RMON compatible management station. An RMON probe is implementable in a network device in conjunction with an agent or outside the network device as a standalone collection mechanism for gathering data for a particular network segment.
RMON is well suited for tracking a number of statistics that represent an operational characteristic of one or more network devices. That is, an RMON probe of a network device stores the gathered information and forwards at the expiration of one or more sampling periods information to an RMON compatible management station.
RFC 1757 defines an RMON events group and an alarm group, which together assist in providing proactive management of a network device. An RMON configured network device can monitor itself or another network device. That is, at the expiration of a predetermined sampling period the network device samples a variable indicating a performance characteristic of the network device, and compares the value of the variable to one or more threshold values. An RMON alarm is generated if the value of the sampled variable crosses a threshold value.
For an RMON probe to sample and evaluate a value of a MIB object instance, the RMON probe must know the object identifier (OID) and instance number associated with the MIB object. However, within an SNMP agent there often exist multiple instances of a MIB object. As such, an RMON probe is often configured with an enumeration of values that identify each instance of the MIB object.
To configure an RMON probe in this manner is time consuming, error prone and as such, burdensome. Moreover, the current network devices support dynamic data, for example, data relating to a session that may or may not be stored after termination of the session. Nevertheless, it is beneficial to monitor statistics on dynamic data. However, because the data is dynamic an RMON probe must be configured to account for all identifiers relating to the dynamic data. Thus configuring an RMON probe with an enumeration of values for use in identifying the dynamic data to monitor is burdensome. Accordingly, there exists a need for a monitoring mechanism having RMON like functionality that automatically accounts for changes in the MIB object instance identifiers having a variable of concern to the RMON probe.